What is metformin found in? Understanding its plant-derived roots and synthetic production

October 11, 2025 •

4 min read

With more than 85 million prescriptions in the United States alone in 2023, metformin is a cornerstone treatment for type 2 diabetes. The answer to the question, "What is metformin found in?", is not a natural food source, but a synthetic chemical derived from a natural compound first discovered in the European plant Galega officinalis, also known as goat's rue.

Quick Summary

Metformin is a synthetic drug chemically synthesized from components related to the plant Galega officinalis, or goat's rue, not extracted directly from it. The plant's compounds led researchers to create safer, more effective biguanide derivatives for medication.

Key Points

Herbal Origin: Metformin's chemical roots trace back to the plant Galega officinalis, also known as goat's rue, a traditional European herbal remedy.
Precursor Compound: The plant contains a chemical called guanidine, which was discovered to have glucose-lowering effects in animals in the early 20th century.
Synthetic Production: The final drug, metformin, is not naturally found in the plant but is a chemically synthesized biguanide derivative produced in a laboratory.
Distinction from Plant: Unlike some natural remedies, metformin is a purified and modified compound, designed to be more effective and safer than earlier, more toxic derivatives.
Modern Medication: Today, metformin is a standard, first-line oral treatment for type 2 diabetes, with its safety and efficacy established through extensive research.
Key Mechanism: It works by decreasing glucose production in the liver and increasing the body's sensitivity to insulin.

The Herbal Ancestry: From Goat's Rue to Guanidine

For centuries, long before the modern era of medicine, extracts from the perennial plant Galega officinalis were used in European folk medicine to treat symptoms associated with diabetes, such as frequent urination. The plant, also known as French lilac or goat's rue, naturally contains a compound called guanidine. In 1918, scientists discovered that guanidine could lower blood glucose levels in animals, sparking intense interest in its potential for diabetes treatment.

Initial explorations into guanidine derivatives, such as galegine and synthalin, began, but these early compounds were eventually discontinued due to unacceptable levels of toxicity. This led researchers to focus on creating safer, more stable derivatives, which eventually included the biguanide class of drugs. This early research laid the foundation for the eventual development of metformin and other similar medications, though the process would be a long and winding one.

The Chemical Synthesis of Metformin

Metformin is a synthetic medication, meaning it is produced in a laboratory and not directly extracted from its ancestral plant source, Galega officinalis. The journey from a plant-based compound to a mass-produced drug highlights a critical distinction in pharmacology. The process involves chemical synthesis, where the final drug is an optimized and refined version of the original compound, designed to be both more effective and less toxic.

The standard industrial process for producing metformin involves reacting dimethylamine hydrochloride with 2-cyanoguanidine under heat. This chemical reaction results in the desired compound, metformin hydrochloride. This controlled, chemical process ensures a consistent, high-purity product, which is essential for pharmaceutical applications. Because of this synthetic process, metformin cannot be found in foods, supplements, or any natural product directly.

Metformin's Journey from Rediscovery to Modern Medicine

Following the disappointment with early, toxic biguanides, metformin was largely forgotten in the pharmaceutical world for a time. It was rediscovered in the 1940s during research into antimalarial agents. French physician Jean Sterne began investigating metformin's glucose-lowering effects, publishing his findings in 1957 and introducing the drug to France. Over the next several decades, metformin gained traction in Europe and Canada, though its approval in the United States was delayed due to concerns related to its more toxic predecessors.

The turning point came with the results of the UK Prospective Diabetes Study (UKPDS) in 1998, which demonstrated long-term cardiovascular benefits for type 2 diabetics taking metformin. This provided crucial evidence of the drug's safety and efficacy, solidifying its role as a first-line treatment for type 2 diabetes worldwide. Its journey illustrates how persistence in scientific research, even after setbacks, can lead to the development of life-changing medications.

Inactive Ingredients in Metformin Tablets

While the primary active component is synthetic metformin hydrochloride, the final tablet contains a variety of inactive ingredients, or excipients, that play a vital role in its delivery and stability. These ingredients are used for different purposes during manufacturing:

Binders: Such as povidone (K-30) and pregelatinized starch, hold the tablet together.
Lubricants: Including magnesium stearate, prevent the tablets from sticking to the manufacturing equipment.
Coatings: Which often contain hypromellose and polyethylene glycol, help with swallowing and can control the release of the drug.

Comparison of Natural Compound vs. Synthetic Drug


Feature	Galega officinalis (Goat's Rue)	Metformin Hydrochloride (Synthetic)
Origin	Natural plant found in Europe and Asia.	Synthetic compound produced in a laboratory.
Active Component	Contains guanidine, the precursor compound.	Pure, synthesized metformin.
Potency	Variable depending on the plant extract; less potent than the synthetic drug.	Consistent, precisely dosed, and more potent.
Toxicity	Early derivatives were found to be too toxic for safe medical use.	Much safer due to controlled chemical modification.
Medical Use	Historically used in folk medicine for diabetes symptoms.	Approved modern medication for type 2 diabetes.

Conclusion: A Testament to Pharmaceutical Science

The history of metformin is a powerful example of how modern pharmacology can leverage centuries-old herbal knowledge to develop safe and highly effective medications. The simple answer to what metformin is found in is that it isn't, in its final form, found anywhere in nature. It is the result of a deliberate and precise synthetic process that was inspired by natural compounds. This process allowed scientists to overcome the toxicity limitations of early plant-derived compounds, leading to the development of one of the most widely used and trusted medications for managing type 2 diabetes and related conditions today. Its story underscores the importance of scientific rigor in translating natural remedies into reliable and accessible treatments for global health challenges.

For more detailed information on metformin's history and mechanism of action, the PubMed article "Metformin: historical overview" provides an authoritative look at its development.

Frequently Asked Questions

No, metformin is not a natural medication. While it was inspired by a compound found in the plant Galega officinalis, it is a synthetic drug that has been chemically modified and refined to be a safe and effective pharmaceutical.

No, you cannot get the benefits of metformin by consuming goat's rue. The plant contains a precursor compound, and early derivatives were too toxic for safe medical use. The synthetic process is necessary to create the safe and precisely dosed medication.

Metformin was created synthetically to increase its safety and efficacy. Early attempts with plant-derived compounds were found to be toxic, and the synthetic process allows for precise control over the final product's composition and potency.

The plant that inspired metformin's development is Galega officinalis, commonly known as goat's rue or French lilac.

Metformin belongs to the biguanide class of drugs, a group of compounds derived from guanidine.

Metformin's U.S. approval was delayed due to concerns about toxic side effects associated with other, earlier biguanide drugs, like phenformin, which had been removed from the market.

Yes, metformin tablets contain several inactive ingredients (excipients), including povidone, pregelatinized starch, and magnesium stearate, which aid in manufacturing and drug delivery.

The manufacturing of metformin is a controlled, industrial chemical synthesis process involving specific chemical compounds, while herbal medicine typically involves using raw or extracted plant material. The synthetic process ensures purity and standardized dosage.

While some compounds like berberine have been studied, it's crucial to consult a doctor before considering alternatives. Natural substances are not a substitute for a prescription medication and may have different safety and efficacy profiles.